1. Field of the Invention
The present invention relates generally to fluid flow rate control devices for controlling the rate of fluid flow from a fluid source to a remote location. More particularly, the invention concerns a novel, readily adjustable flow rate control device having a novel flow control plate that is positioned intermediate a fluid supply line and a fluid delivery line. The flow control plate is provided with a plurality of elongated fluidic flow control channels that are in communication with a rate selector member that is rotatably carried by the device housing. Rotation of the rate selector member places a selected one of the flow control channels in communication with the fluid delivery line and precisely controls the rate of fluid flow from the fluid source toward the remote location.
2. Discussion of the Prior Art
A number of in-line fluid flow controllers for use in controlling the rate of fluid flow from a fluid supply line into a fluid delivery line have been suggested in the past. These types of devices are used in a wide variety of applications where it is necessary to control the rate at which fluid flows from a fluid source to a remote delivery point via fluid supply and delivery lines.
A frequently used application of prior art fluid flow devices is to control the rate of infusion of a fluid medicament from a source of fluid medicament into the body of a patient. Examples of such prior art devices are described in U.S. Pat. No. 6,095,491 issued to one of the present inventors. This patent describes a readily adjustable flow rate control device having a movable flow control member which includes a plurality of spaced-apart flow restrictors which are adapted to be selectively positioned intermediate to a fluid flow path extending between a fluid supply line and a fluid delivery line. In one form of this prior art device the flow restrictors take the form of a plurality of porous rate control frits which can be selectively moved into index with the fluid flow path.
Another prior art fluid flow control device is described in U.S. Pat. No. 5,499,968 issued to Milijasevic, et al. This patent describes various constructions of in-line fluid flow controllers which are adapted primarily for use with a conventional fluid administration set of the type used for infusion of fluid into the body of a patient. In one embodiment, the Milijasevic, et al., fluid flow controllers comprise a housing, a chamber therein and an inlet to and an outlet from the chamber. The housing is adapted to receive therewithin at least one flow restrictor having an orifice configured to control the rate of fluid flow therethrough and into the body of the patient. In an alternate embodiment, the controller is adapted with a series of fluid passageways, which are linked with a series of orifice plates held in position by a wedge.
Another somewhat similar prior art fluid flow rate control device is disclosed in U.S. Pat. No. 4,781,698 issued to Parren. The Parren device comprises a conventional roller clamp, which is connected to a drop chamber. The drop chamber controls the size of the droplets flowing toward the roller clamp and the roller clamp controls the rate of fluid flow through the delivery line. The Parren apparatus includes a disk having a discharge opening which is selectively alignable with one or more drop tubes and includes a flexible edge or wiper means formed around the discharge opening to provide a seal between the disk and the selected drop tube to prevent fluid from seeping between the disk and the mounting plate.
A common drawback of many of the prior art flow controllers is that the controllers are often complex in construction, are difficult and costly to manufacture, are often somewhat unreliable and lack ease of adjustability to quickly and easily vary the rate of fluid through the device. The thrust of the present invention is to overcome these drawbacks by providing a compact, readily adjustable, highly precise flow rate control device which is easy to install within a fluid system, is easy to use and is particularly well-suited for use in connection with medicament dispensers for precisely dispensing medicaments to a patient in a home care environment.